The battery builders club

Yeah ots alot of power ikr
Im living in the alps so i really want a torqui mountainboard and no my weight is about 180 lbs

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Ok got it thx very much

Ok maybe ill go for 6p then not sure yet as i need to figure out how much space i have left on my board
Bit thx very much to you guys

Itā€™s still a beast of a battery either way

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Yeah what i really like tht its still giving me a good amount of range although it has not tht many p groups

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Lol ya coming from me who is about to build a 12s9p brick 30q pack, if I had the money, I would have done 12s7p of 42a

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Crazy pack of power man where do you put it in?

Custom made 3d printed top mount

There will be a build thread as soon as I get around to it, first mountainboard for me

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It was actually cheaper for me to build a 12s8p P42A than it was to build a 12s8p 30Q.

I think 30Q was like $4.95/cell and P42A $4.70/cell.

Yeah well I already have over 108 30q so free for me

Otherwise there would have been no question. My number is 25mi offroad

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ok ill have to look at the price / performance ratio of both cells now before i finally decide which one i pick

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Itā€™s most likely the P42A in every way. More current, capacity, and best price because you need less P42A to match the 30Q. Even smaller total size, and the bigger cells are easier to build with.

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I thought max continuous A for the P42As was 30A cts?

Was there a change to the battery since this test was done?

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so there it says it 40A can be used when the battery cell doesnt is under 75 degree
i dont think my battery ever got above 60 degree

I never have problems with my batteries heating up. They only get slightly above ambientā€¦ maybe Iā€™m not pushing them hard enough lol.

Iā€™ve went from lipos to 8p 18650 then to 8p 21700ā€¦

that probably explains it :grin:

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think the 30T is the way for me it costs 3,5ā‚¬ and the pa42 6,5ā‚¬
thx for the info man now i need to rethink my whole battery mounting :wink:
ohh noooo ;-(

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Just a few side notesā€¦

  • Molicel rates their cells for non-continuous use, how their large commercial customers use them (power tools, vacuum cleaners, etc.). The P42Aā€™s rating of 45A (by Molicel) can give you the stated cycle life if you stay under 75Ā°C. That is the internal cell temperature. The cell could feel just warm from the outside of a pack and be pretty toasty internally.

  • I rate Molicels lower because those are my estimates for the cellā€™s true continuous current rating for decent cycle life. That allows for direct comparison of the Molicel to other cells. My rating isnā€™t the ā€œcorrectā€ one. Itā€™s the one I use to allow for these comparisons.

  • Thereā€™s no one ā€œcorrectā€ rating. It all depends how the cells are being used and what your priorities are. If very long cycle life is mandatory then the P42A might be given a 20A rating with a 60Ā°C max temp. If cycle life is secondary and pure power is needed then they could be given a 50A rating. They will not last long though at that level and your risks go up.

  • How hard you use a cell is up to you. Any of them can be run at a level far above its continuous current rating. But the performance will be crap, the cellā€™s overall life shortened, and the risk of problems eventually popping up increases. Some people care about these things but others only care that they have a certain amount of space for their pack and are going to use that pack hard.

  • Iā€™ll always recommend staying at or below a cellā€™s continuous current rating even if youā€™re only pulsing the cell, especially with ultra-high capacity cells with lots of internal resistance (which causes voltage sag). Staying below the rating helps the cell run more efficiently (less voltage sag), increases the overall life of the cell, and reduces risks. Itā€™s your call though. Use them the way you want to. I just ask that we first take the time to make an educated decision, understanding the tradeoffs and risks.

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Donā€™t threaten me with a good timeā€¦

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Thx for the detailled testing ive read through it and now its clearer why the pa42s dont really provide 42a for the eskate purpose (in case you want them to last for a while)

I think ill do a samsung 30t pack now with16s5p as the cells are cheaper and the amp rating is also good
Thx for the info on this guys!!
@ZachTetra
@ShutterShock
@Battery_Mooch

Thx very much!!

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How would a manufacturer/testing facility actually measure the internal temperature of a cell under load?